For example, as an electric arc melting facility for melting a source iron, such as scrap, there is known an electric arc melting facility structured to continuously feed a source iron, such as scrap, and to use exhaust gas to preheat the source iron to be charged (for example, Patent Document 1). This electric arc melting facility includes a melting chamber for melting the source iron, a preheating chamber directly connected to an upper side of the melting chamber and configured to preheat the source iron by the exhaust gas generated in the melting chamber, an arc-generating electrode for melting the source iron in the melting chamber, a source iron feeding means for feeding the source iron to the preheating chamber, and a tap hole formed in the melting chamber. Further, a thrusting device or pusher is disposed at a lower side of the preheating chamber and configured to feed or transfer the source iron from inside the preparatory chamber into the melting chamber.
In general, a pusher of this type includes a pusher main body for pushing forward the push-target object, i.e., source iron, and a cylinder, such as a hydraulic cylinder, for driving the pusher main body. The pusher main body is inserted into and retracted from the preparatory chamber by the cylinder to feed the source iron into the melting chamber.
According to the electric arc melting facility described in the Patent Document 1, the source iron is continuously or intermittently fed to the preheating chamber to maintain a state in which the source iron exists continuously over the preheating chamber and the melting chamber. Along with this operation, the pusher is inserted into and retracted from the preheating chamber charged with the source iron to feed the source iron from inside the preheating chamber into the melting chamber. The source iron is melted by the electric arc inside the melting chamber, and the melting chamber is thereby filled with molten steel, at which time the pusher is stopped. Then, the molten steel is heated by the arc to increase the temperature thereof, and is tapped while the source iron exists continuously over the preheating chamber and the melting chamber.